It is important to know about the hazards which could affect our communities. The more we know about them the better we can plan for them causing an emergency:

• Earthquakes
• Flooding
• Storms
• Tsunami
• Manmade/Technological

Earthquakes

You know what they say, "When you want to know something, go to the expert!" That is why you should visit these sites to learn all about earthquakes: www.gns.cri.nz - www.quaketrackers.ac.nz

Earthquakes present the most significant hazard to South Canterbury as well as other parts of New Zealand. We do not experience them very frequently but they have the most capacity to cause widespread damage.

Of all the earthquake sources that can affect Canterbury the Alpine Fault is the most studied. It is capable of generating a very large earthquake which will affect much of the South Island. It will produce the strongest earth shaking experienced in South Canterbury since European settlement.
Of course, there are other known fault lines in South Canterbury (and probably some we do not know about). Earthquakes are a very real hazard and their occurrence must be planned for.

Flooding:

This is Canterbury's (and probably New Zealand's) most frequent emergency.

Declared Emergencies Caused by Flooding

16.03.1986
Declaration for Strathallan County, Waimate Combined District, Temuka Borough and Timaru City.1,160 people evacuated from Pleasant Point and 200 people from Seadown.One person was killed. Insurance claims totalled $27.2 million (1994).Road and rail damage was estimated at $30.65 million (1991). Agricultural assistance estimated at $4.67 million. (1991).

11.08.1986
Declar

ation for Milford Riding (Strathallan County) and Temuka Borough.65 evacuated.Agricultural assistance $4.79 million (1991).

09.01.1994
Declaration for Mt Cook (Mackenzie District).150 people evacuated.

19.03.1994
Declarations for Timaru, Waimate and Mackenzie Districts.In total, appropriately 240 people evacuated.Approximately $5.5 million damages, including $3 million damage to state highways.

14.12.1995
Declarations for Omarama (Waitaki District) and Hakataramea (Waimate District).Total of 52 people evacuated.Extensive damage to one lane bridges across the Waitaki River.

06.02.1997
Declaration for Timaru District.Opuha Dam failure while under construction.About 200 people evacuated.

The Canterbury Plains were formed by alluvial gravels being deposited from the many rivers which cross them. Since European settlement, we have built communities on the plains and then tried to protect them from flooding by building stopbanks. Because the stopbanks are quite effective, more and more intensive land use of flood plains has occurred. That is okay until a flood exceeds the design of the stopbanks or they breach. Then people and property on the flood plain are in danger!

If you live, work, or your school, is on a flood plain, you are at risk. You should inform yourself about that risk. Environment Canterbury has produced flood plain maps and staff there can tell you about the flood risk. Here is an example of a map:

Many of the rivers in Canterbury build up to a flood over a period of time, ranging from hours to days. Some, however, flood with little or no warning, eg Kowhai Stream at Blandswood where three children lost their lives in a flash flood.

It is very important to understand the flood risk. You need to know what depth of water you could expect and how fast moving it could be (velocity). You also need to know the likelihood of getting flooded.

Environment Canterbury can be contacted on: (03) 687 7800

You can check out river level and rain information on their website: www.ecan.govt.nz